546 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



IDMONEA, FILIFORMIS, new species 



Plate 84, figs. 1-3 



The zoarium is free, delicate, filiform, sinuous, bifurcated almost 

 always at a right angle. The fascicles are little salient, divergent 

 toward the zoarial margin, alternate on each side of the median line, 

 not projecting. The tubes are distinct, separated by a slight furrow 

 in groups of two to the fascicle, with rectangular peristome. The 

 dorsal is ornamented with large curved, transverse wrinkles. 



Measurements. — Diameter of peristome, 0.08 mm.; distance be- 

 tween fascicles, 0.50-0.58 mm.; number of tubes to fascicle, 2; width 

 of branches, 0.50 mm. 



Affinities. — The general aspect is that of Idmonea gracillima Busk, 

 1875, but the present species differs in the presence of two tubes to 

 the fascicle. Moreover, Busk's species belongs to the genus Crisiona 

 Canu and Bassler, 1927. 



Occurrence.— D. 5478. Tacbuc Point, Leyte; 10° 46' 24" N.; 125° 

 16' 30" E.; 57 fathoms, Sh. 



Cotypes. —C&t. No. 8399, U.S.N.M. 



IDMONEA PARVULA, new species 



Plate 85, fig. 1 



Description. — The zoarium is free, small, filiform, bifurcated, with 

 triangular section, borne on a little expanded, circular base. The 

 fascicles are salient, diverging toward the zoarial margins, alternating 

 on each side of the median crest. The tubes are distinct, separated 

 by a little visible thread, grouped in 2 or 3 to a fascicle, with thin 

 square peristome. The ovicell is a long narrow sack arranged on the 

 zoarial crest. The dorsal is striated longitudinally and transversely. 



Measurements. — Diameter of peristome, 0.09 mm.; distance of 

 fascicles, 0.28; number of tubes to fascicle, 2 or 3; and width of 

 branches 0.40. 



Variations. — The dorsal is superbly marked. The longitudinal striae 

 are little visible but the transverse striae are curved and grouped 

 in distinct zones. 



Affinities. — This species differs from Idmonea fliformis, new 

 species, in its much smaller branches and its less scattered fascicles. 



Occurrence.— D. 5478. Tacbuc Point, Leyte; 10° 46' 24" N.; 125° 

 16' 30" E.; 57 fathoms; Sh. 



Cotypes.— Cat. No. 8400, U.S.N.M. 



